workercells to synthesize the target products. However, when an exogenous gene is introduced into workers, they are all troubled by a common problem—
genetic instability, which can be caused by random gene mutations, horizontal gene transfer, genome rearrangement and the activities of mobile DNA elements, etc . Due to the inevitable instability, workers will not stop evolving towards
cheatercells who get rid of the extra metabolic burden.
natural colonies, workers will cooperate to synthesize and secrete
public substances into the environment for the population to use, but cheaters will always emerge in the course of evolution. To maintain the balance of colony, a policing mechanism is also developed through evolution. In response to the cheaters, workers will transform into
guardcells who can secrete a cytotoxin to selectively target cheaters.
universal cheater-proof platformfor protein production to detect and kill the cheaters in colony. We designed the genetic pathways in
workers and guardsrespectively, allowing guards to recognize mutated cheaters and specifically eliminate them. Based on our platform, users can choose from two monitoring mechanisms, adjust killing intensity and observe the mCherry fluorescent strength as an index of the cheaters’quantity.
 Darmon E, Leach DR. Bacterial genome instability. Microbiol Mol Biol Rev. 2014 Mar;78(1):1-39. doi: 10.1128/MMBR.00035-13. PMID: 24600039; PMCID: PMC3957733.
 Wang M, Schaefer AL, Dandekar AA, Greenberg EP. Quorum sensing and policing of Pseudomonas aeruginosa social cheaters. Proc Natl Acad Sci U S A. 2015 Feb 17;112(7):2187-91.